Car is Draining Battery

[Mr. Wolfe]

Hi guys, my name is Greg Wolfe and I am somewhat new to the e30. My other car is a 2006 BMW M3 ZCP (interlagos/black). This past weekend I bought a 1987 BMW 325is Bronzit/Cardinal. The car is very clean, but has one minor problem (hopefully) - if you leave it over night with the battery connected, the car will drain the battery. Does anyone have any clue of where I should begin to look for the culprit before I decide to take it somewhere?

Thanks for ANY help!

Mr. Wolfe

[Bullhead]

Check to make sure the light inside the glove box is turning off when closed. The switch on the door can sometimes get sticky and the light will stay on. The best way is to check the fuse panel with an ohm meter. While the car is off with the battery still hooked up test the fuses to see which one's are still using current (DC Current on the meter). This will show you where the problem is in a general sense.

[MoreMayhem]

Does it have an aftermarket alarm? Mine did and it sucked... the battery dry.
Removed it all and the battery would still go flat if it sat for a couple days. Turned out that the trunk light wasn't shutting off.

[Mr. Wolfe]

Thanks for all of the help guys. I do not think it has an aftermarket alarm. I will post my results when I figure it out. The car won't be in my possession until this evening. Again, thanks for offering some possible faults.

Mr. Wolfe

[TimeMachinE30]

Your battery healthy?

[Mr. Wolfe]

Your battery healthy?

I think so. It fires up VERY strongly every time. The previous owner said only when left over night does it go dead. The past 2 nights the battery was off and fired up strongly the next morning. My friend drove it back from Ohio so this is him talking and not the previous owner.

Mr. Wolfe

[Dan_Wright]

Without seeing anything obvious, like any electronic or light staying on when it shouldn't be, you can test where the drain is coming from with a multi-meter.

Measure amperage in series from the negative terminal to the ground on the battery. Shouldn't be above 50-60 milliamps iirc.
If you do measure some sort of drain, start pulling fuses until the amperage goes down, and the fuse you pull will indicate where the drain is coming from.

[Mr. Wolfe]

Without seeing anything obvious, like any electronic or light staying on when it shouldn't be, you can test where the drain is coming from with a multi-meter.

Measure amperage in series from the negative terminal to the ground on the battery. Shouldn't be above 50-60 milliamps iirc.
If you do measure some sort of drain, start pulling fuses until the amperage goes down, and the fuse you pull will indicate where the drain is coming from.

Thanks Dan. I am going to dig into this tomorrow at some point. I will post my findings. :up:

Mr. Wolfe

[3BEEPS]

any update I am having the same problem

[dnguyen1963]

http://www.wikihow.com/Find-a-Parasitic-Battery-Drain

[3BEEPS]

http://www.wikihow.com/Find-a-Parasitic-Battery-Drain

thanks for this